Since the inception of electric circulation and inline heaters, there has been a general design principal of placing a heating element into a flowing stream of fluid or material. This element is typically mounted in a flow channel or fluid housing which maintains and envelops the heating element such that the fluid passes over the heating element picking up the energy produced by the heating element. This design is very efficient in nature and is a mainstay among all process and product applications given the inherent capabilities and efficiencies.
Conventional heater technologies include the cartridge style heater where a resistive circuit is coiled and set within a closed end tube and then back filled with dielectric heat transfer materials. This heater design is then incorporated into a housing if it is to be used to heat a moving fluid for forced flow or convective heating.
Another conventional design is a resistive circuit enclosed within a tube surrounded and backfilled by dielectric/heat transfer material, most commonly Magnesium Oxide (MgO2). This style heater is very versatile with configurations including hairpin patterns, corkscrew coils, spring patterns etc. However, all of these winding designs must be included within an additional housing for use as a fluid heater either forced flow or convective flow, otherwise the movement of the fluid will not be channeled across the element making it useless as an effective fluid heater.
A supplementary heating device currently available on the market incorporates a resistive heater as described in either of the above examples with a formed aluminum body which translates the heat energy produced by the heater through the cast aluminum body then into the flow channel carrying the heated media.